Hydraulically controlled gear driven drive axles are an efficient way of controlling the speed and direction of land vehicles, such as walk behind and ride-on lawnmowers, ATV, and tractors. Some known hydraulically controlled drive units include high reduction mechanical gearing that can compromise the relative smoothness of the control of the vehicle. In addition, these drive units may be inherently limited in the amount of ground engaging power, and thus unable to put more than a limited amount of the engine's horsepower into ground engaging tasks. This affects control, accuracy and longevity of the transaxle as well as compromising the vehicle's performance and otherwise limiting the vehicles applications.
Other known ground engaging transaxles are substantial in design and weight. Piston powered pumped units, while adaptable, have their own requirements and restrictions including the need for separate motors or the need of an associated gear transmission to apply power to the ground. While these known drive systems are functional, their compromise in cost and performance of each design is apparent.